<template>
  <div
    ref="rootRef"
    class="suggest"
    v-loading:[loadingText]="loading"
    v-no-result:[noResultText]="noResult"
  >
    <ul class="suggest-list">
      <li
        class="suggest-item"
        v-if="singer"
        @click="selectSinger(singer)"
      >
        <div class="icon">
          <i class="icon-mine"></i>
        </div>
        <div class="name">
          <p class="text">{{ singer.name }}</p>
        </div>
      </li>
      <li
        class="suggest-item"
        v-for="song in songs"
        :key="song.id"
        @click="selectSong(song)"
      >
        <div class="icon">
          <i class="icon-music"></i>
        </div>
        <div class="name">
          <p class="text">{{ song.singer }}-{{ song.name }}</p>
        </div>
      </li>
      <div
        class="suggest-item"
        v-loading:[loadingText]="pullUpLoading"
      ></div>
    </ul>
  </div>
</template>

<script>
import { ref, watch, computed, nextTick } from 'vue'
import { search } from '@/service/search'
import { processSongs } from '@/service/song'
import usePullUpLoad from './use-pull-up-load'
export default {
  name: 'suggest',
  props: {
    query: String,
    showSinger: {
      type: Boolean,
      default: true
    }
  },
  emits: ['select-song', 'select-singer'],
  setup(props, { emit }) {
    const singer = ref(null)
    const songs = ref([])
    const hasMore = ref(true)
    const page = ref(1)
    const loadingText = ref('')
    const noResultText = ref('抱歉，暂无搜索结果')
    const manualLoading = ref(false)

    const loading = computed(() => {
      return !singer.value && !songs.value.length
    })

    const noResult = computed(() => {
      return !singer.value && !songs.value.length && !hasMore.value
    })

    const pullUpLoading = computed(() => {
      return isPullUpLoad.value && hasMore.value
    })

    const preventPullUpLoad = computed(() => {
      return loading.value || manualLoading.value
    })

    const { isPullUpLoad, rootRef, scroll } = usePullUpLoad(
      searchMore,
      preventPullUpLoad
    )

    watch(
      () => props.query,
      async newQuery => {
        if (!newQuery) {
          return
        }
        await searchFirst()
      }
    )

    async function searchFirst() {
      if (!props.query) {
        return
      }
      page.value = 1
      songs.value = []
      singer.value = null
      hasMore.value = true

      const result = await search(props.query, page.value, props.showSinger)
      songs.value = await processSongs(result.songs)
      singer.value = result.singer
      hasMore.value = result.hasMore
      await nextTick()
      await makeItScrollable()
    }

    async function searchMore() {
      if (!hasMore.value || !props.query) {
        return
      }
      page.value++
      const result = await search(props.query, page.value, props.showSinger)
      songs.value = songs.value.concat(await processSongs(result.songs))
      hasMore.value = result.hasMore
      await nextTick()
      await makeItScrollable()
    }

    async function makeItScrollable() {
      if (scroll.value.maxScrollY >= -1) {
        manualLoading.value = true
        await searchMore()
        manualLoading.value = false
      }
    }

    function selectSong(song) {
      emit('select-song', song)
    }

    function selectSinger(singer) {
      emit('select-singer', singer)
    }
    return {
      singer,
      songs,
      loadingText,
      noResultText,
      loading,
      noResult,
      pullUpLoading,
      selectSong,
      selectSinger,
      // pullUpLoad
      rootRef
    }
  }
}
</script>

<style lang="scss" scoped>
.suggest {
	height: 100%;
	overflow: hidden;
	.suggest-list {
		padding: 0 30px;
		.suggest-item {
			display: flex;
			align-items: center;
			padding-bottom: 20px;
			.icon {
				flex: 0 0 30px;
				width: 30px;
				[class^='icon-'] {
					font-size: 14px;
					color: $color-text-d;
				}
			}
			.name {
				flex: 1;
				font-size: $font-size-medium;
				color: $color-text-d;
				overflow: hidden;
				.text {
					@include no-wrap();
				}
			}
		}
	}
}
</style>
